In answer to the original post, I have experienced the very same issue. It was due to a bad convertor that I believe never switched from bulk mode and essentially cooked the batteries. My wife complained when we first got the unit that whenever she was near the front of the trailer she smelled the sewer. It was grossing her out. Me too. I finally discovered that it was coming from the battery box vent. Batteries were less than a couple of months old. I would always have to do the hydraulics in manual mode a section at a time. Either the batteries were junk from the start, or the charger was bad. Anyway, I replaced the whole mess with a power block from big battery and haven't looked back. 12V, 170Ah, self monitoring, over charge/under charge protection, battery monitor and kill switch in one neat little package. Everything works as it should now and no maintenance. Click image for larger version. 

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